﻿/* Copyright (c) 2019 Rick (rick 'at' gibbed 'dot' us)
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would
 *    be appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not
 *    be misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source
 *    distribution.
 */

using System;
using System.Windows.Input;

namespace Gibbed.Gearbox.WPF
{
    public class DelegateCommand<TType> : ICommand
    {
        private readonly Predicate<TType> _CanExecute;
        private readonly Action<TType> _Execute;

        public event EventHandler CanExecuteChanged;

        public DelegateCommand(Action<TType> execute)
            : this(execute, null)
        {
        }

        public DelegateCommand(Action<TType> execute, Predicate<TType> canExecute)
        {
            this._Execute = execute;
            this._CanExecute = canExecute;
        }

        public bool CanExecute(object parameter)
        {
            if (this._CanExecute == null)
            {
                return true;
            }

            return this._CanExecute((TType)parameter);
        }

        public void Execute(object parameter)
        {
            this._Execute((TType)parameter);
        }

        public void RaiseCanExecuteChanged()
        {
            this.CanExecuteChanged?.Invoke(this, EventArgs.Empty);
        }
    }
}
